Choriocapillaris microvasculature dysfunction in systemic hypertension

Abstract

We examined the choriocapillaris microvasculature using a non-invasive swept-source optical coherence tomography angiography (SS-OCTA) in 41 healthy controls and 71 hypertensive patients and determined possible correlations with BP and renal parameters. BP levels, serum creatinine and urine microalbumin/creatinine ratio (MCR) specimens were collected. The estimated glomerular filtration rate (eGFR) was calculated based on CKD-EPI Creatinine Equation. The main outcome was choriocapillaris flow deficits (CFD) metrics (density, size and numbers). The CFD occupied a larger area and were fewer in number in the hypertensive patients with poor BP control (407 ± 10 µm2; 3260 ± 61) compared to the hypertensives with good BP control (369 ± 5 µm2; 3551 ± 41) and healthy controls (365 ± 11 µm2; 3581 ± 84). Higher systolic BP (β = 9.90, 95% CI, 2.86-16.93), lower eGFR (β = - 0.85; 95% CI, - 1.58 to - 0.13) and higher urine MCR (β = 1.53, 95% CI, 0.32-2.78) were associated with larger areas of CFD. Similar significant associations with systolic BP, eGFR and urine MCR were found with number of CFD. These findings highlight the potential role of choriocapillaris imaging using SS-OCTA as an indicator of systemic microvascular abnormalities secondary to hypertensive disease.

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1

Distribution of (A) density, (B) size and (C) number of choriocapillaris flow deficits (CFD) in participants without hypertension (healthy controls), hypertensives with good blood pressure control and hypertensives with poor blood pressure control. Data and P values shown are after adjustment for age, gender, race and body mass index. Hypertensives with poor blood pressure control had the largest and fewest CFD than hypertensives with good blood pressure control and healthy controls.

Figure 2

Swept source optical coherence tomography angiography (SS-OCTA; 3 × 3 mm2 area) and color‐coded maps indicating regions of choriocapillaris flow deficits (CFD) (B, D and F) of a choriocapillaris vascular layer of a healthy control individual (Top panel; A–B), a hypertensive with well-controlled blood pressure (Middle panel; C–D), and a hypertensive with poorly controlled blood pressure (Bottom panel; E–F). Hypertensives with high BP tended to have larger sized CFD (F; labelled as yellow). The presence of flow deficits is areas of dark regions in the angiogram (A, C and E) and their sizes are color‐coded (B, D and F). Images (A, C and E) were generated from the built-in review software (PLEX Elite Review Software, Carl Zeiss Meditec, Inc., Dublin, USA; Version 1.7.1.31492; https://www.zeiss.fr/content/dam/Meditec/international/ifu/documents/plex-elite/current/2660021169042_rev_a_artwork.pdf). The images (B, D and F) were generated from MATLAB software (The MathWorks, Inc.; Version R2018b; https://www.mathworks.com/products/new_products/release2018b.html).

Figure 3

Schematic log–log plot concerning flow deficits where the data follow a y = mx + b slope intercept relationship between the number of flow deficits and size of flow deficits. Flow deficits that are larger regions, as shown along the right side of the slope, are more likely to occur in persons with poorly controlled blood pressure (BP).

Figure 4

Scatterplots showing (A) positive correlation of size of flow deficits with systolic blood pressure and (B) negative correlation of number of flow deficits with systolic blood pressure in participants without hypertension (healthy controls; green), hypertensives with good blood pressure control (red) and hypertensives with poor blood pressure control (green).